Apparatus for converting solidified powders of ores loaded in ore transport ships into slurries

ABSTRACT

In apparatus for converting a solidified powder of ore loaded in an ore transport ship into a slurry of the type wherein a high pressure water jet is supplied to the bottom of the solidified powder of ore so that a cavity is formed at the bottom of the solidified powder at the early stage of the converting operation, means is provided for admitting atmospheric air into the cavity.

Waited States Patent 11 1 Sakata et al.

[ Apr. 24, 1973 APPARATUS FOR CONVERTING SOLIDIFIED POWDERS OF ORES LOADED IN ORE TRANSPORT SHIPS INTO SLURRIES Inventors: Masanobu Sakata; Kenichi Nagata; Shigeru Nagamori, all of lchihara; Hideo Suzuki, Yachiyo, all of Japan Assignee: Mitsui Shipbuilding & Engineering Co., Ltd., Tokyo, Japan Filed: May 31, 1972 Appl. No.: 258,291

Foreign Application Priority Data June 7, l97l Japan ..46/40044 Int. Cl ..B65g 53/30 Field of Search ..302/l4, l5; 214/14,

ll T

[56] References Cited UNITED STATES PATENTS 3,606,036 9/l97l Beehe et al. ..302/l4 X Primary Examiner-Evon C. Blunk Assistant Examiner-Hadd S. Lane Attorney-C. Yardley Chittick et al.

[5 7] ABSTRACT In apparatus for converting a solidified powder of ore loaded in an ore transport ship into a slurry of the type wherein a high pressure water jet is supplied to the bottom of the solidified powder of ore so that a cavity is formed at the bottom of the solidified powder at the early stage of the converting operation, means is provided for admitting atmospheric air into the cavity.

3 Claims, 8 Drawing Figures Patented April 24, 1973 5 Sheets-Sheet 1 PRIOR ART PRIOR ART Patented April 24, 1973 3 Sheets-Sheet 2 F/G.4I

Patented April 24, 1973 3,729,232

5 Sheets-Sheet 5 BACKGROUND OF THE INVENTION This invention relates to apparatus for converting a powder of ore into a slurry for unloading the ore from an ore transport ship.

In an ordinary ore transport ship the ore is loaded in the form of a fine powder 3 in a tank 2 of the ship 1. Although the powder 3 is loaded as a slurry but when it is transported to a destination it dries and coagulates into a solid lump so that it is necessary to reconvert it into a slurry at the destination. For the sake of brevity such dry lump of the powder of oreis herein called as a solidified powder." For this purpose, clean water is supplied througha pipe 4 from the shore, pressurized by a high pressure pump 5, and the pressurized water is ejected upon the powder through a nozzle 7 of an ejector 6 to convert the powder into a slurry as-shownin FIG. 1. The resulting slurry is sentto the shore by a slurry pump 8 through an unloading pipe 9. At the initial stage of the unloading operation, a cavity is formed at the bottom of the powder as shown in FIG. 1 and this space is filled with water or slurry. Under such conditions the high pressure water ejected from the nozzle 7 loses its kinetic energy by agitating the water in the space 11 in the cavity so.that the ejected water is no more effective to break the inner wall of the cavity, thus decreasing the concentration of the discharged slurry. In the later stage of the unloading operation when the volume of the cavity increases, the powder of the ore above the cavity falls'down to form an open cavity as shown in FIG. 2 with the result that the water jets come to directly impinge upon the inner wall of the cavity thereby efficiently breaking the wall :and assuring high concentration of the resulting slurry required for high speed unloading. As above described, with the prior art apparatus, due to the low .concentration of slurry at the early stage of the unloading operation, it takes many times to reconvert theore'into the slurry thus decreasing the unloading speed.

SUMMARY OFTI-IE INVENTION It is therefore an object of this invention to provide an improved apparatus for converting a solidified powder of ore loaded in an ore transport ship which can efficiently form the slurry thus decreasing the unloading time.

A further object of this invention is to provide an improved apparatus for converting the solidified ore into a slurry of the desired concentration without being interferred by a cavity formed at the bottom of the solidified ore at the early stage of the converting operation.

In accordance with this invention, in apparatus for converting a solidified powder of ore loaded in an ore transport ship into aslurry of the type wherein a high pressure water jet is supplied to the bottom of the solidified powder of ore so that a cavity is formed at the bottom of the solidified powder at the early stage of the converting operation, means is provided for admitting atmospheric air into the cavity. The air maybe admitted under the atmospheric pressure or after compression. The air admitted into the cavity is effective to purge the water or siurry in the cavity out of the cavity so that the water jet can directly impinge upon the inner wall of the cavity thus readily disintegrating the solidified powder into the slurry.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings: FIGS. 1 and 2 show diagrammatic cross-sectional views of an ore transport ship equipped with a conven- 0 tional apparatus for converting a powder of ore into a slurry in which FIG. 1 shows an early stage and FIG. 2 an advanced stage of the converting operation;

FIGS. 3 to 5 show similar cross-sectional views of an ore transport ship equipped with diffefent types of the apparatus of this invention for converting a powder of ore into a slurry;

FIG. 6 shows a longitudinal section of one example of a high pressure water ejector; and

FIGS. 7 and 8 are sectional views of the ejector shown in FIG. 6 taken along lines VII VII and VIII VIII, respectively. Throughout the drawings the like or corresponding elements are designated by the same reference numerals.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment shown in FIG. 3, an air suction pipe 12 is addedto the apparatus shown in FIGS. 1 and 2 between the atmosphere or a space above the deck of the ship and the bottom of the ore tank 2. As the pressure in the cavity 10 is decreased below the atmospheric pressure when the slurry formed in the bottom of the cavity is discharged by slurry pump 8 through discharge pipe 9, atmospheric air is sucked into the cavity 10 through air suction pipe 12 and fills the vacant space 11 within the cavity 10. Accordingly, the water jet ejected from ejector 7 can directly impinge upon and crush the inner wall of the cavity without being interferred with the slurry or water in the cavity. I

When the suction power of the slurry pump is not sufficient so that the pressure in the cavity is higher than the atmospheric pressure, an air compressor 13 may be included in air suction pipe 12 as shown in FIG. 4 to forcibly discharge the slurry or water filling the cavity 10. In the modification shown in FIG. 5, the pressurized air from air compressor 13 is discharged through an annular opening 14 surrounding the water ejecting nozzle 7 of the ejector 6. It is advantageous to make equal the speed of the compressed air ejected from annular opening 14 and the speed of the pressurized water ejected from the nozzle'7 so as to eject the pressurized water to more remote positions for more efficiently crushing the solidified powder of ore to convert it into a slurry.

FIG. 6 shows a vertical section of a rotary ejector 6 suitable for use in the embodiment shown in FIG. 5. More particularly, the ejector 6 is driven by a vertical rotary shaft 17 and extends upwardly-through a stationary housing 16. The interior of the housing 16 is divided into'a upper chamber 19 communicated with the output of the air compressor 13 and a lower chamber 20 communicated with the output of water pump 5. The lower end of the central passage 21 through ejector 6is communicated with water chamber 20 and the upper end is terminated in nozzle 7. The lower end of the outer passage 22 through nozzle 6 is communicated with air chamber 19 and is terminated in annular opening 14 at the upper end. Suitable packings 15 are provided between the sliding surfaces of housing 16 and ejector 6 to prevent leakage of the pressurized air and water.

As above described, in accordance with this invention it is possible to positively discharge the water in a cavity which is formed at the bottom of the solidified powder of the ore at the early stage of the operation for converting the powder into a slurry thereby causing the water jet to directly impinge upon and crush the inner wall of the cavity. This increases the concentration of the slurry and decreases the unloading time. When compressed air is ejected around the high pressure water jet, the effective range of the jet water is increased whereby the crushing efficiency of the jet water can be improved.

While the invention has been shown and described in terms of some preferred embodiments thereof it will be clear that many changes and modifications will be obvious to one skilled in the art without departing from the true spirit and scope of the invention as defined in the appended claims.

What is claimed is:

1. In apparatus for converting a solidified powder of ore loaded in an ore transport ship into a slurry of the type wherein a high pressure water jet is supplied to the bottom of said solidified powder of ore so that a cavity is formed at the bottom of said solidified powder at the early stage of the converting operation, the improvement which comprises means for admitting atmospheric air into said cavity. I

2. The improvement according to claim 1 which comprises an air compressor for supplying said air.

3. The improvement according to claim 2 which comprises a rotary water ejector mounted at the bottom of a tank containing said powder of ore for ejecting said high pressure water jet, and wherein said rotary water ejector is provided with an annular air opening surrounding said water jet, said annular air opening being connected to the output of said air compressor. 

1. In apparatus for converting a solidified powder of ore loaded in an ore transport ship into a slurry of the type wherein a high pressure water jet is supplied to the bottom of said solidified powder of ore so that a cavity is formed at the bottom of said solidified powder at the early stage of the converting operation, the improvement which comprises means for admitting atmospheric air into said cavity.
 2. The improvement according to claim 1 which comprises an air compressor for supplying said air.
 3. The improvement according to claim 2 which comprises a rotary water ejector mounted at the bottom of a tank containing said powder of ore for ejecting said high pressure water jet, and wherein said rotary water ejector is provided with an annular air opening surrounding said water jet, said annular air opening being connected to the output of said air compressor. 